Feeding mechanism for sewing machines



April '18, 1933. N. E. HANSON FEEDING MECHANISM FOR SEWING MACHINES Filed 001;. 1931 6 Sheets-Sheet 1 (Ittorneg A ril 18, 1933. N. E. HANSON 1,903,762

\ FEEDING MECHANISM FOR SEWING MACHINES Filed Oct- 2, 1951 6 Sheets-Sheet 2 Snnentor attorney's A ril 18, 1933. N. E. HANSON FEEDING MECHANISM FOR SEWING MACHINES File C 1931 6 Sheets-Sheet 3 April 18, 1933. N. E. HANSON 1,903,762

FEEDING MECHANISM FOR SEWING MACHINES Filed Oct. 2, 1931 6 Sheets-Sheet 4 J Ennenkor flWw QM (Ittorneg April 18, 1933. N. E. HANSON FEEDING MECHANISM FOR SEWING MACHINES Filed Oct. 2, 1951 6 Sheets-Sheet 5 Snventor' April 18 1933. Nit-1. HANSON FEEDING MECHANISM FOR SEWING MACHINES Filed Oct. 2, 1931 6 Sheets-Sheet 6 Patented Apr. 18, 1933 NATHAN a. anson, on cn eneo,,- itn nors, nssie von T union srnoiAL MACHINE Y O A Y qr GH AG tumo a GQRP BA N or ILLINOIS FEEDING immense va ss i MAQHINES Applicatipn f led October 2, 1931. Serial No. 566,537.

The invention relates to new and useful improvements in a feeding mechanism for sewing machines, and more particularly to a differential feeding mechanism.

An object of the invention is to provide a feeding mechanism which is Ivery'compact and of few parts so that the feed dogs and the mechanism for opera-ting the same may be placed in a relatively small space, such as a tubular work supporting arm for feed: ing the material around or across the arm as it is being stitched.

A further object of the invention is to provide a feeding mechanism of the above pe wherein the main and auxiliary feed dogs are both operated from an eccentrically set rotating member through devices which give to one of said feed dogs a difierent feeding stroke.

' A still further object of the invention is to provide a feeding mechanism of the above type wherein the feed dogs rece ve their feeding movements from an eccentrica lly set rotating member'which carriesa device eecentrically set thereon so that different feed.-

ing movements are imparted to "the feed dogs.

A still further object of the invention is to provid a feeding mechanism of the above type with means for adjusting said device so that the relative length of the feed strokes may be varied. H

These and other objects will in part be obvious and will in part be'hereinafter more fully described.

In the drawings which show ';by way of illustration one embodiment of the invention- Figure 1 is :a front view of a sewing machine in which the invention is embodied;

Fig. 2 is an end view of a portion of the machine with the end cap broken aw t show the feeding mechanism within the work arm;

Fig. '3 is a horizontal longitudinal section through the work arm showing the looper and the feeding mechanism with the feed dogs removed for the sake of c'learness';

Fig. i is a vertical sectional view showing the mechanism within the work arm' in side elevation, the feed dogs being removed;

Fig. 5 is a sectional view through the work arm on the line 55 of Fig. 6;

. Fig. 6 is a view partly in horizontal section and partly in plan of the end of the work arm;

Fig. '7 is a sectional view through the operating parts Within the work arm on the line 7-'.-.7 of Fig. 4;

Fig. 8 is a sectional view of the operating parts within the work arm on the line 88 of Fig. .4;

Fig. 9 is a sectional View through the operating parts within the Work arm on the line 9..9 of Fig. 4, and

Fig. 10 is a perspective view of the parts of the feeding mechanism at the end of the work arm, said parts being separated in order to show the structure more clearly.

The invention is directed to a feeding mechanism for sewing machines, and more particularly to a sewing machine having a cylindrical or tubular work supporting arm, and wherein it is desired to feed the material across or around the arm as it is being stitched. The main shaft of the machine extends longitudinally of the work arm. The

feed rockers is mounted on the yoke so that they may be raised or lowered. The feed rockers are both oscillated from an eccentric member at the end of the main shaft, which is in the form of a crank pin secured to the shaftso that it can beadjusted radially of the-shaft. 'Mounted on the crank pin is a sleeve-which is concentric to the center of the pin and which has a ribbed connection with ,the' block on the end of the shaft, so that this sleeve is always retained in a fixed angular position on the crank pin, but is adjustable with the crank pin to diflerent set positions. Also mounted on this crank pin is a second sleeve which has a radial rib and groove connection with the first-named sleeve. The opening through this last-named sleeve is radially enlarged so as to permit said sleeve to be shifted to different set positions on the crank pin and secured thereto. The feed rocker on which the main feed dog is mounted has a rocker fork straddling the firstnamed sleeve, and the feed rocker carrying the auxiliary feed dog has a rocker fork for straddling the second-named sleeve. As the main shaft rotates, the two feed rockers will be oscillated and thus feeding movements imparted to the feed dogs. In view of the fact that the second-named sleeve may be set eccentrically on the crank pin, the movements imparted to the two feed dogs may be of different lengths, and thus a differential feed ing mechanism is provided.

Referring more in detail to-the drawings, the invention is shown as applied to a sewing machine including a standard 1 carrying an overhanging arm 2 in which a ne dle bar 3 reciprocates. Said needle bar carries two needles 4. 4 with which a loo er 5 cooperates. The needle bar is reciproca ed b a needle lever 6 operated by an eccentric strap 7 coopcrating with an eccentric on the main shaft. The looper 5 is fixed to a looper bar 8 which is mounted for oscillation and endwise movements in suitable hearings in the work arm which is indicated at 9 in the drawings. The looper support is moved longitudinally of the work arm by a link 10 which is connected through a suitable mechanism 11 to an arm 12 carried by the needle lever 6. The looper is oscillated by a fork 13 cooperating with an eccentric on the main shaft which is indicated at 14. Thus it is that the lo-oper is moved so as to cooperate with the needles in the stitch formation. Cooperating with the needles above the work support, is a cross thread laying mechanism which includes a thread guide 15 and a thread hook 16 oscillated by means of a link 17 connected to the needle lever extension 12. These parts which form the stitch are all of the usual construction and will not need further detail description.

The invention has to do particularly with the feeding mechanism which feeds the material to the stitching devices. The feeding mechanism includes a main feed dog 18 and an auxiliary feed dog 19. The auxiliary feed dog is preferably located well in front of the needles, and in the stitching of certain fabrics, it is given a movement of a slightly greater extent than the main feed dog, and the feeding mechanism is, therefore, known as a differential feeding mechanism. The feed dog 18 is mounted on a feed rocker 20. The feed rocker 20 is provided with a rib 21 and the feed dog 13 is carried by a shank 22 having a groove 23 therein which receives the rib 21. A screw 24 is passed through an opening 25 in the shank and is threaded into the feed rocker 20, and thus the main feed dog is rigidly attached to the feed rocker 20 which supports and operates the same. The auxiliary feed dog 19 is mounted on a feed rocker 26. Said auxiliary feed dog 19 is carried by a shank 27 which fits within a seat 28 in the feed rocker 26. A screw 29 threaded through the shank and into the feed rocker securely holds the auxiliary feed dog rigidly attached to the feed rocker 26.

Extending along the work supporting arm 9 is a shaft 30 which is mounted in suitable bearings, and on the end of the shaft is attached ayoke 31 provided with two arms 32 and 33. A pin 34 is mounted in these two arms 32 and 33, and on this pin, the feed rockers 20 and 26 are mounted. The pin has a reduced concentric portion 35 which fits within the opening 36 in the arm 33. It also has a concentric portion fitting within the opening 37 in the arm 32. This lastnamed concentric portion is of larger diameter and is provided with a slot 38 extending diametrically thereof, which may be used for turning the pin to different set positions. The pin is held in set positions by a set screw passing through the opening 39 in the arm 32. This pin has an eccentric portion 40. The feed rocker 20 has an opening 41 therethrough which receives this eccentric portion 40. The feed rocker 26 has an opening 42 therethrough which receives the enlarged concentric portion of the pin 34. The shaft 30 extends parallel with the main shaft and is provided with a collar 43 secured to the shaft by means of screws 44, 44. This shaft has forked arms which engage and cooperate with an eccentric 45 on the main shaft 14. As the main shaft rotates, this shaft 30 will be oscillated and will raise and lower the pin 34 supporting the feed rockers, and thus it is that the feed dogs are moved into and out of engagement with the material. By adjusting the pin 34 the position of the feed rocker 20 may be shifted relative to the feed rocker 26. Thus the feed dogs may be leveled and properly spaced from each other.

Mounted on the end of the main shaft 14 is a head or block 46 having a T-slot 47 extending diametrically across the same. Mounted in this slot is a crank pin 48. The crank pin is adjustable radially of the axis of the shaft 14. This is accomplished by an adjustingscrew 49 held from endwise movement by a bracket 50 and threaded into the head supporting the crank pin 48.

Mounted on this crank pin 48 is a sleeve 51. The sleeve 51 is provided with a flange 52 and a rib 53 extending diametrically across the flanged head of the sleeve. The opening 54 through the sleeve is of substanteeetea tially the same size. as the; crank pin 4.8. This ment on the crank pin. The; sleeve and crank pin are adjusted together to diff r nt:

set positions, and the, sleeve remains concenw tric: to the. longitudinal center axis of the crank pin 48. On the outer end of the sleeve, 51 is a projecting rib 5'5v which extends diametrically across. the flanged head 56 on the sleeve: 51, The. rocker 20 carrying the main feed dog 18 is provided with a rocker fork 57. The two. arms of the rocker fork; 57 straddle the sleeve 51 and, lie between the flanged heads on this, sleeve. As. the. main shaft, isv rotated, the rocker 20.: will be. oscih lated, and thus a feeding movement impart: ed to the feed dog. The extent of feeding movement imparted to. the main feed dog dependsupon the setting of the crank pin 48.

Also mounted on the crank pin 48 is a sleeve 58 which is, provided with a flanged head 59 having radial grooves 60 adapted to receive the rib 55 on the sleeve 51. The opem ing 61 through this sleeve 58, is radially elongated so as to permit the sleeve t be radially shifted on the crank pin l8; and in a direction lengthwise of the rib 55 Av washer 62 is placed on the crank pin and bears against the end of the sleeve 58'f0r1n; ing a flanged head therefor. A nut 63 is threaded on to the crank pin, and firmly clamps the sleeve 58 in a set position on the crank pin. The feed rocker 26 is provided with a rocker fork 64, the arms of which straddle the sleeve 58 and lie between the flanged head 59 and the washer 62. When the main shaft rotates, the rocker 26. will be oscillated. If this sleeve 58 is set so that it is eccentric to the longitudinal axis of the crank pin 48, then the oscillation imparted to the rocker 26 will be of a different character from the oscillation imparted to the rocker 20. By shifting the position of the sleeve 58, the eccentricity thereof is-varied and the extent of movement imparted to the auxi iary feed dog likewise varied.

It will be noted from the above that both feed dogs are operated from the same ec centrically set member, which, in the-illustrated form of the invention, is the crank pin 48, and at the same time, the feed dogs are given different feeding strokes. The number of parts constituting the feeding mechanism are very few, and these are very compactly arranged so that the feeding mechanism may be placed in a tubular work supporting arm of small dimensions. The feed dogs are positively raised and lowered and positively moved back and forth. lVhile the invention is particular y adapted to a machine of the type disclosed, it will be understood that the manner of operating the feed dogs from a single eccentrically set p siti n, and t e same time nse ng eth d dog d ferenti l m vement, maybe used in ther ypes o ma hin a d he mech ism r mp r ing the feeding mew merits, to. the feed dogs gr a y r d Wi hout departing from thespirit of the inven-. tion as set forth in the appended claims.

Having thus, described the invention, what. cl imed asnew and d sired to be e u by Lette s-P en 1. A f eding me h n sm or e ing Inachines comprising a main feed dog, an auxiliaryfeed clog, mean for suppor ing, and a s ing and lowering said feed dogs, means for imparting feeding movements, to said feed dogs including a rotating shaft, an eccentrie cally disposed member carried thereby, means, operated by said eccentrically disposed meme her for imparting feed movements. to one of said feed dogs, a device carriedby said, eccentric member and receiving movements therefrom, and means operated by said device for imparting feeding movements to the other feed dog, said device being disposed eccenw trically on said eccentrically disposed me1n-.

ber whereby a differential movement. is imparted to the feed dog operated thereby.

2. A feeding mechanism for sewing n1a chines comprising a main feed dog, auxila iary feed dog, means for supporting and raising and lowering said feed dogs, means for imparting feeding movements to. said feed dogs including a shaft, an eccentrically disposed member carried thereby, means oper-v ated by said eccentrically disposed member for imparting feed movements to one of said feed dogs, a device carried by'said eccentric member, and means operated by said device for imparting feeding movements to the other feed dog, said device being adjustably sup.-.

ported by said eccentric member so. that said device may be set eccentrically on said member whereby a differential movement is imparted to the feed dog operated thereby.

3. A feeding mechanism for sewing machines comprising a main feed dog, an auxiliary feed dog, means for supporting and raising and lowering said feed dogs, means for imparting feeding movements to said feed dogs including a shaft, an eccentric-ally dis-v I;

posed member carried thereby, means oper: ated by said eccentrically disposed member for imparting feeding movements to said feed dog, a sleeve carried by said eccentrieally diss posed member and shiftable radially thereon to different set positions, and means operated by said sleeve for imparting feeding movements to the other feed dog.

l. A feeding mechanism for sewing machines comprising a main feed dog, a feed rocker on which said main feed dog is mounted,j an auxiliary feed dog, an independent feed rocker on which said auxiliary feed dog is mounted, means for suppor ing s i k r f r aising an lett ri g said feed dogs, means for oscillating said feed rockers for imparting feeding movements to said dogs including a shaft, an eccentrically disposed member carried thereby, a device cooperating with said member and said feed rocker carrying the main feed dog for oscillating said rocker, and a device mounted on said eccentrically disposed member, receiving movements therefrom, and connected to the rocker supporting the auxiliary feed dog for oscillating the same.

5. A feeding mechanism for sewing machines comprising a main feed dog, a feed rocker on which said main feed dog is mounted, an auxiliary feed dog, an independent feed rocker on which said auxiliary feed dog is mounted, means for supporting said rockers for raising and lowering said feed dogs, means for oscillating said feed rockers for imparting feeding movements to said feed dogs including a shaft, an eccentrically disposed member carried thereby, a device cooperating with said member and said feed rocker carrying the main feed dog for oscillating said rocker, a device mounted on said eccentrically disposed member and connected to the rocker supporting the auxiliary feed dog for oscillating the same, and means whereby said last-named device may be shifted radially of the eccentric member to different set positions thereon for varying the differential movement imparted to the feed dogs.

6. A feeding mechanism for sewing machines comprising a main feed dog. an auxiliary feed dog, independent feed rockers supporting said dogs, a shaft, a yoke carried by said shaft and having means for supporting said feed rockers, means for operating the shaft for raising and lowering the feed rockers. a main shaft, a crank pin carried by said main shaft, one of said feed rockers having a rocker fork engaging said crank pin, a member mounted on said crank pin and shiftable radially thereof to different set positions, the other of said feed rockers having a rocker fork engaging said shiftable member.

7. The combination of a work supporting arm, a main rotating shaft extending lengthwise of said arm and a feeding mechanism disposed in said arm and including a main feed dog, an auxiliary feed dog, means for supporting and raising and lowering said feed dogs, an eccentrically disposed member carried by the end of said main shaft, means operated by said eccentrically disposed memher for imparting feed movements to one of said dogs, and a device carried by said eccentrically disposed member and receiving movements therefrom for imparting feed movements to the other feed dog, said device being adapted to be set eccentrically on said eccentrically disposed member for imparting a differential movement to the feed dog carried thereby.

8. The combination of a work supporting arm, a main rotating shaft extending lengthwise of said arm and a feeding mechanism disposed in said arm and including a main feed dog, an auxiliary feed dog, means for supporting and raising and lowering said feed dogs, an eccentrically disposed member carried by the end of said main shaft, means operated by said eccentrically disposed member for imparting feed movementsto one of said dogs, a device carried by said eccentrically disposed member and receiving movements therefrom for imparting feed movements to the other feed dog, said device being adapted to be set eccentrically on said eccentrically disposed member for imparting a differential movement to the feed dog carried thereby, and means whereby said eccentrically disposed member may be adjusted radially of the shaft for varying the extent of throw of both feed dogs.

9. The combination of a work supporting arm, a main rotating shaft extending lengthwise of said arm and a feeding mechanism disposed in said arm and including a main feed dog, an auxiliary feed dog, means for supporting and raising and lowering said feed dogs, an eccentrically disposed member carried by the end of said main shaft, means operated by said eccentrically disposed member for imparting feed movements to one of said dogs, a device carried by said eccentrically disposed member and receivin movements therefrom for imparting feed movements to the other feed dog, said device being adapted to be set eccentrically on said eccentrically disposed member for imparting a differential movement to the feed dog car ried thereby, and means whereby said device may be shifted to different set positions on said eccentrically disposed member.

10. The combination of a work supporting arm, a main rotating shaft extending lengthwise of said arm and a feeding mechanism disposed in said arm and including a main feed dog, an auxiliary feed dog, means for supporting and raising and lowering said feed dogs, an eccentrically disposed member carried by the end of said main shaft, means operated by said eccentrically disposed member for imparting feed movements to one of said dogs, a device carried by said eccentrically disposed member and receiving movements therefrom for imparting feed movements to the other feed dog, said device being adapted to be set eccentrically on said eccentrically disposed member for imparting a diiferential movement to the feed dog carried thereby, means whereby said device may be shifted to diflerent set positions on said eccentrically disposed member, and means whereby said eccentrically disposed member may be adjusted radially of the shaft for varying the feed stroke of the feed dogs.

11. The combination of a work supporting arm, a main shaft extending lengthwise of said arm, an auxiliary shaft in said arm parallel to said main shaft, means carried by the main shaft for oscillating said auxiliary shaft, a main feed dog, an auxiliary feed dog, feed rockers disposed side by side and supported for oscillation by said auxiliary shaft so that the oscillation of the shaft will raise and lower said feed dogs, an eccentrically disposed member carried by the end of said main shaft, one of said rockers having a rocker fork engaging said eccentrically disposed member, a device carried by said eccentrically disposed member, and the other of said feed rockers having a rocker fork engaging said device, said device being adapted to be shift-ed to an eccentric position on said eccentrically disposed member.

12. The combination of a Work supporting arm, a main shaft extending lengthwise of said arm, an auxiliary shaft in said arm parallel to said main shaft, means carried by the main shaft for oscillating said auxiliary shaft, a main feed dog, an auxiliary feed dog, feed rockers disposed side by side and supported for oscillation by said auxiliary shaft so that the oscillation of the shaft will raise and lower said feed dogs, an eccentrically disposed member carried by the end of said main shaft, one of said rockers having a rocker fork engaging said eccentrioally disposed member, a device carried by said eccentrically disposed member, and the other of said feed rockers having a rocker fork engaging said device, said device being adapted to be shifted to an eccentric position on said eccentrically disposed member, and means whereby said eccentrically disposed member may be adjusted radially of said main shaft.

13. The combination of a Work supporting arm, a main shaft extending lengthwise of said arm, an auxiliary shaft in said arm parallel to said main shaft, means carried by the main shaft for oscillating said auxiliary shaft, a main feed dog, an auxiliary feed dog, feed rockers disposed side by side and supported for oscillation by said auxiliary shaft so that the oscillation of the shaft will raise and lower said feed dogs, a crank pin mounted for radial adjustment on the end of said main shaft, a sleeve on said crank pin, means for preventing said sleeve from angular movement on said crank pin, one of said feed rockers having a rocker fork adapted to straddle said sleeve, a second sleeve on said crank pin and mounted for radial adjustment on the crank pin, and means for preventing said second sleeve from angular movement on said crank pin, the other feed rocker having a rocker fork adapted to straddle said second sleeve.

1 1. The combination of a work supporting arm, a main shaft extending lengthwise of said arm, an auxiliary shaft in said arm parallel to said main shaft, means carried by the main shaft for oscillating said auxiliary shaft, a main feed dog, an auxiliary feed dog, feed rockers disposed side by side and supported for oscillation by said aux-- iliary shaft so that the oscillation of the shaft will raise and lower aid feed dogs, a crank pin mounted for radial adjustment on the end of said main shaft, a sleeve on said crank pin, means for preventing said sleeve from angular movement on said crank pin, one of said feed rockers having a rocker fork adapted to straddle said sleeve, a second sleeve on said crank pin and mounted for radial adjustment on the crank pin, and means for preventing said second sleeve from angular movement on said crank pin, the other feed rocker having a rocker fork adapted to straddle said second sleeve, said second sleeve being connected to the first sleeve so as to permit adjustment and be held from angular movement on the crank pin, said other feed rocker having a rocker fork adapted to straddle said second sleeve.

In testimony whereof, I affix my signature.

NATHAN E. HANSON. 

